Avoid spurious "The compiler crashed" messages in batch mode.

tests/compiler/dart2js/dart2js_batch_test.dart

Index: tests/compiler/dart2js/dart2js_batch_test.dart
diff --git a/tests/compiler/dart2js/dart2js_batch_test.dart b/tests/compiler/dart2js/dart2js_batch_test.dart
index 8afe9e981dd7831555d73445e8adf01d5991ec3a..04b3ad670e4f65945b143607daa50470309a0faa 100644
--- a/tests/compiler/dart2js/dart2js_batch_test.dart
+++ b/tests/compiler/dart2js/dart2js_batch_test.dart
@@ -74,9 +74,7 @@ Future runTests(Process process) {
   return Future.wait([output, errorOut])
         .then((result) {
       String stdoutOutput = result[0];
-      print('out:\n$stdoutOutput');
       String stderrOutput = result[1];
-      print('err:\n$stderrOutput');
 
       Expect.equals(4, ">>> EOF STDERR".allMatches(stderrOutput).length);
       Expect.equals(4, ">>>".allMatches(stderrOutput).length);